docs: def avglosses_data_transfer(token, dstore):
      """
      Determine the amount of average losses transferred from the workers to the
      controller node in a risk calculation.
      """
      oq = dstore['oqparam']
      N = len(dstore['assetcol'])
      R = dstore['csm_info'].get_num_rlzs()
      L = len(dstore.get_attr('risk_model', 'loss_types'))
      ct = oq.concurrent_tasks
      size_bytes = N * R * L * 8 * ct  # 8 byte floats
      return (
          '%d asset(s) x %d realization(s) x %d loss type(s) losses x '
          '8 bytes x %d tasks = %s' % (N, R, L, ct, humansize(size_bytes)))